small grammar fixes

CONTRIBUTING.md

-# Contribution Guideline
+# Contribution Guidelines
 
-Thanks for considering to contribute this project. All issues and pull requests are highly appreciated.
+Thanks for your interest in contributing this project. All issues and pull requests are highly appreciated!
 
 ## Pull Requests
 
-Before sending pull request to this project, please read and follow guidelines below.
+Before sending a pull request to this project, please read and follow guidelines:
 
-1. Branch: We only accept pull request on `master` branch.
-2. Coding style: Follow the coding style used in DoraemonKit.
-3. Commit message: Use English and be aware of your spell.
-4. Test: Make sure to test your code.
+1. Branch: We only accept pull requests on the `master` branch
+2. Coding style: Follow the coding style used in DoraemonKit
+3. Commit message: Use English and check your spelling
+4. Test: Make sure to test your code
 
 Add device mode, API version, related log, screenshots and other related information in your pull request if possible.
 
-NOTE: We assume all your contribution can be licensed under the [Apache License 2.0](https://github.com/didi/DoraemonKit/blob/master/LICENSE).
+NOTE: We assume all contributions can be licensed under the [Apache License 2.0](https://github.com/didi/DoraemonKit/blob/master/LICENSE).
 
 ## Issues
 
 We love clearly described issues. :)
 
-Following information can help us to resolve the issue faster.
+The following information can help us resolve the issue faster:
 
-* Device mode and hardware information.
-* API version.
-* Logs.
-* Screenshots.
-* Steps to reproduce the issue.
+* Device mode and hardware information
+* API version
+* Logs
+* Screenshots
+* Steps to reproduce the issue